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1.
Flight dynamics theories are influenced by two major topics: how birds adapt their flight to cope with heterogeneous habitats, and whether birds plan to use the wind field or simply experience it. The aim of this study was to understand the flight dynamics of free-flying Cory’s shearwaters in relation to the wind characteristics on the coastal upwelling region of continental Portugal. We deployed recently miniaturised devices—global positioning system loggers to collect precise and detailed information on birds’ positions and motions. Prevalent winds were blowing from the north-east and adults used those winds by adjusting their flight directions mainly towards north-west and south-west, flying with cross and tail winds, respectively, and avoiding head winds. This is confirmation that Cory’s shearwaters use a shear soaring flying strategy while exploiting the environment for food: adults foraged mainly with cross winds and their ground speed was not constant during all foraging trips as it changed dynamically as a result of the ocean surface shear winds. During travelling phases, ground speed was strongly influenced by the position of the bird with regard to the wind direction, as ground speed increased significantly with increasing tail wind component (TWC) values. Adults appear to choose foraging directions to exploit ambient wind, in order to improve shear soaring efficiency (cross winding) and exploit diurnal changes in tail wind strength to maximise commuting efficiency. We report, for the first time, precise ground speed values (GPS-derived data) and computed actual flight speed values (using TWC analysis) for Cory’s shearwater. 相似文献
2.
The most common invasive mammals??mice, rats, and cats??have been introduced to islands around the world, where they continue to negatively affect native biodiversity. The eradication of those invasive mammals has had positive effects on many species of seabirds. However, the removal of one invasive mammal species may result in abundance changes of other species due to trophic and competitive interactions among species. Understanding the overall impact of several invasive species is a key challenge when evaluating the possible effects of eradication programmes. Here we assess the influence of the three most common invasive mammals on nest survival of Cory??s shearwater ( Calonectris diomedea). We monitored six breeding colonies over 3?years and measured the activity of mice, rats and cats to examine the influence of invasive mammals on nest survival. We found that nest survival showed a similar temporal trend in all years, with lowest weekly survival probabilities shortly after chicks hatched. Cats were identified as major predators of chicks, but no measure of colony-specific cat activity was able to adequately explain variation in shearwater nest survival. Nest survival was on average 0.38 (95?% confidence interval 0.20?C0.53) and varied among colonies as well as over time. We found a small positive influence of rats on nest survival, which may indicate that the presence of small rodents as alternative prey may reduce cat predation of chicks. Our findings suggest that the eradication of rodents alone may exacerbate the adverse effects of cats on shearwater nest survival. 相似文献
3.
Global economic and population growth increase the extent and intensity of artificial night lighting. From an ecological perspective, this is light pollution, which causes changes in reproductive physiology, migration and foraging of many species and ultimately leads to loss of biodiversity. Some seabirds are intimately linked with the light features of their environments because they are nocturnally active. We report light-induced groundings of Cory’s shearwater ( Calonectris diomedea) during a 2-year study (2008 and 2009) in São Miguel Island, in the Azores archipelago, and investigate the spatial correlation of locations of grounded birds with an annual composite of remotely sensed stable lights. Results indicate that 16.7% of fledglings are attracted to lights. The exposure of shearwater colonies in the study area to artificial night lighting is low overall. Four colonies account for 87% of the grounded birds. The distance each bird was found from the closest colony was best explained by the ratio of the satellite-measured light levels at the grounding spot to the light levels at the assigned colony of origin. These results demonstrate that satellite-observed nighttime lights are sufficient to assess risk to marine birds at the scale of oceanic islands and indicate their utility for monitoring the effectiveness of programs to manage lighting to reduce risk for these species and conducting global assessments of species vulnerability. To minimize the impact on Cory’s shearwater and other marine birds, we recommend measures such as reduction and control of lighting intensity near colony locations, while continuing and re-enforcing rescue campaigns. 相似文献
4.
Brood-guarding (or the continual attendance at the nest by one parent) has been relatively little studied in altricial birds.
Parental investment in brood-guarding is often highly variable within a species, and the study of such variability may contribute
to the understanding of the functions and regulation of this behaviour and of the trade-offs involved in the choice between
attending the nest and leaving to forage. In some colonial birds, it has been found that early nesting pairs attend their
chick for longer than later nesting counterparts, giving rise to the synchronisation hypothesis that suggests that early pairs prolong brood-guarding in order to reduce the probability of nest predation by a dilution
effect. In this paper, for the first time we test the prediction that burrow-nesting colonial birds subject to little predation
pressure should not display a seasonal decline in brood-guarding duration. The growth assistance hypothesis suggests that brood-guarding may allow the provision of frequent small meals and the efficient use of energy by chicks with
poor homeothermic capabilities, resulting in improved early chick-growth. Finally, the chick-protection hypothesis predicts that chicks in more exposed nests should be brood-guarded for longer. Data collected at two Cory’s Shearwater Calonectris diomedea colonies situated in contrasting environments supported the synchronisation hypothesis, as there was no seasonal trend in
brood-guarding duration. Contrary to the growth assistance hypothesis, chicks brood-guarded for longer periods did not have
an improved growth (in one colony there was even a negative effect of brood-guarding on early chick development). Finally,
we found no difference in brood-guarding between nests with contrasting levels of exposure to potential predators and weather.
Despite confirming the prediction of the synchronisation hypothesis, more research is needed to identify the main factors
underlying the variability of brood-guarding observed in this and other studies. 相似文献
6.
The etiology of sporadic Parkinson’s disease (PD) is unknown, although mitochondrial dysfunction and oxidative stress have
been implicated in the mechanisms associated with PD pathogenesis. Dopamine (DA) neurons of the substantia nigra pars compacta
have been shown to degenerate to a greater extent in PD than other neurons suggesting the possibility that DA itself may be
contributing to the neurodegenerative process. This review discusses our work on the effects of DA oxidation and reactive
DA quinones on mitochondrial function and protein modification and the potential for exacerbating toxicity associated with
mitochondrial dysfunction in PD. 相似文献
7.
The recent rediscovery of what is perhaps the most iconic and the world’s largest wild bee species, endemic from just a handful islands in Indonesia, represents a major finding and opens up new avenues for conservation research on this species thought to be extinct. But there is one twist in this otherwise positive insect conservation tale: two female specimens of Megachile pluto collected on Bacan (Indonesia) in February and on Halmahera (Indonesia) in September 2018 (respectively) appeared on an international online auction site, and fetched several thousands of US$ each to private collectors. These online sales marks a new chapter in bee conservation, and will likely present important new policy and scientific challenges to protect this species from extinction. Indeed, while Wallace’s Giant Bee is currently red listed according to the International Union for Conservation of Nature, the international trade of this species is currently not restricted as it does not appear on the appendices of the Convention on International Trade in Endangered Species. Wider implications are discussed to highlight how the case study of Wallace’s Giant Bee also applies to other threatened insect species subject to international trade, and how conservation actions should be developed. 相似文献
8.
Home Care Services (HCS) aim at providing complex coordinated health care for patients at their homes. This paper addresses the challenges of routing and scheduling HCS caregivers under precedence and coordination constraints, with patients receiving multiple caregivers. Moreover, the visits are performed simultaneously and possibly in a predefined order. The routing problem involves a fleet of vehicles to serve a number of customers at different locations. The objective is to find the minimal round for vehicle, while satisfying all the customers and without violating customers’ time windows. It has been proved that the complexity of the caregivers routing problem is linked to both (1) the number of care activities per caregiver ratio and (2) the temporal dependencies rate. Given the poor performance of the mathematical modeling based on exact approaches, a heuristic approach called the Caregivers Routing Heuristic (CRH) has been developed and tested using real size instances. In fact, the exact approaches are not able to solve real size instances. The performance of the CRH has been evaluated using real size instances. The numerical results show that the CRH is very efficient in terms of computation times. Otherwise, the CRH is less sensitive than the exact approaches to both complexity axes: the temporal dependencies constraints and the ratio of the number of care activities per caregiver. 相似文献
9.
Mediterranean European Union member states have to deal with thousands of migrants arriving by sea every year. Frontex (the EU external borders agency) organizes joint surveillance operations at sea to interdict these migrant boats, helping states to cope with the problem. This article discusses the legality of these maritime interdictions done by Frontex according to the international law of the sea as well as the conformity of the operations with the nonrefoulement principle. 相似文献
11.
IntroductionAccording to genome wide association (GWA) studies as well as candidate gene approaches, Behçet’s disease (BD) is associated with human leukocyte antigen (HLA)-A and HLA-B gene regions. The HLA-B51 has been consistently associated with the disease, but the role of other HLA class I molecules remains controversial. Recently, variants in non-HLA genes have also been associated with BD. The aims of this study were to further investigate the influence of the HLA region in BD and to explore the relationship with non-HLA genes recently described to be associated in other populations. MethodsThis study included 304 BD patients and 313 ethnically matched controls. HLA-A and HLA-B low resolution typing was carried out by PCR-SSOP Luminex. Eleven tag single nucleotide polymorphisms (SNPs) located outside of the HLA-region, previously described associated with the disease in GWA studies and having a minor allele frequency in Caucasians greater than 0.15 were genotyped using TaqMan assays. Phenotypic and genotypic frequencies were estimated by direct counting and distributions were compared using the χ 2 test. ResultsIn addition to HLA-B*51, HLA-B*57 was found as a risk factor in BD, whereas, B*35 was found to be protective. Other HLA-A and B specificities were suggestive of association with the disease as risk (A*02 and A*24) or protective factors (A*03 and B*58). Regarding the non-HLA genes, the three SNPs located in IL23R and one of the SNPs in IL10 were found to be significantly associated with susceptibility to BD in our population. ConclusionDifferent HLA specificities are associated with Behçet’s disease in addition to B*51. Other non-HLA genes, such as IL23R and IL-10, play a role in the susceptibility to the disease. 相似文献
12.
Capsule: The Western Bonelli’s Warbler Phylloscopus bonelli has a nest success of only 25% in the core of its range in western Europe. Aims: To investigate the breeding biology of Western Bonelli’s Warbler P. bonelli, focusing on possible altitude effects and potential reproductive problems. Methods: Three Western Bonelli’s Warbler populations were monitored during the 2012 and 2013 breeding seasons in the massif range of Sierra Nevada, Spain. We determined all the breeding parameters and calculated daily survival and success rates for each reproductive period. Results: The three studied populations did not differ in any breeding parameters. Altitude showed a positive relationship with clutch size and duration of incubation period, but a negative relationship with nestling tarsus growth and body mass gain. Daily survival rates during incubation and nestling periods were similar to those of common warblers, but the species presented a low breeding success of 25%. Conclusion: The absence of differences among the three populations suggests that the information provided here could be representative of its distribution in the woodlands of Sierra Nevada. The novel and detailed information reported is crucial not only for expanding our understanding of this species but also to draw attention to the potential risks that it might face in the near future, considering the reduction that this species has suffered in Sierra Nevada during recent decades. 相似文献
13.
Energies corresponding to optimum geometries of ninhydrin, some of its analogs, the corresponding Ruhemann’s Purple analogs
and some of the intermediates of the reaction between ninhydrin analogs and amino acids are calculated at Hartree–Fock/6-31G**
level of theory. Such a study is significant from a forensic science point of view because of the strong interest in the forensic
chemistry and law enforcement communities in developing alternatives to the current generation of ninhydrin-like chemicals
for the detection and development of latent fingerprints. In examining our new predictions for the net energetics of the reactions
in the formation of substituted Ruhemann’s Purples, we find that a fluorine-containing analog is the most thermodynamically
feasible reaction. In light of this finding, we suggest further experimental studies to determine the kinetic feasibility
of synthesizing the fluorine-containing analog, as well as other similar molecules and to determine their spectroscopic properties. 相似文献
14.
Seabird life-history traits such as long generation time, low annual fecundity and delayed sexual maturation make them more prone to population loss and consequently to extinction; petrels are indeed amongst the most threatened birds. Based on coalescence and multiloci inference this study examines the extent of genetic differentiation of a vulnerable New Caledonia ( caledonica) and Australia ( leucoptera) subspecies of Pterodroma leucoptera (Gould’s Petrel), and whether the genetic relationship between them results from the influence of past events like variation in sea level, or is dominated by contemporary gene flow. Sequences of two mitochondrial genes and five nuclear introns were obtained from 86 individuals from both populations. Haplotype networks were used to infer relationships between the haplotypes of both populations. The demographic history of the P. leucoptera complex was studied using neutrality tests and Extended Bayesian Skyline Plots. A weak population differentiation was revealed. The Extended Bayesian Skyline plot suggested a population expansion approximately 80,000 years before present (bp) for caledonica and 30,000 years bp for leucoptera. The split was dated to 30,000 years bp by means of multilocus inference through *BEAST. Despite genetic similarity of the two taxa, we advocate to consider them as independent units for conservation management, given their strong ecological distinctiveness (foraging distribution, winter distribution, breeding phenology and breeding distribution). 相似文献
15.
Kenya’s black rhinoceros population declined by more than 98% from 20,000 individuals in the 1970s to around 400 individuals
in 1990 due to the effects of poaching, at which time the surviving individuals were isolated in a series of demographically
inviable subpopulations. An initial management exercise translocated the survivors into four high security sanctuaries to
control poaching and enhance breeding, and this measure successfully arrested the decline. Subsequently, new sanctuaries were
established and the metapopulation size reached 650 animals by 2008. However, translocations and the current management strategy
that partitions the metapopulation into ‘montane’ and ‘lowland’ rhinoceros may have substantial consequences at the population
level and their impact on population genetic diversity has not been investigated. In this study, 12 of the 16 extant subpopulations
were analysed using 408 bp of mitochondrial control region sequence ( n = 170) and nine microsatellite loci ( n = 145). Both markers detected moderate to high genetic diversity ( h = 0.78 ± 0.027, n = 170; H O = 0.70 ± 0.087, n = 145) consistent with previous studies on Diceros bicornis michaeli. However, mtDNA and nDNA diversity varied substantially between subpopulations. The results suggest that the Masai Mara is
more differentiated, inbred and isolated than other subpopulations. It also suggests that there are neither distinct montane
and lowland groups nor other detectable historical barriers to gene flow. Instead the large majority of genetic diversity
was partitioned at the level of individuals; highlighting the need to conserve as many individuals as possible. Future translocations
should consider the genetic profile of individuals and the demographic history of both the donor and recipient subpopulations. 相似文献
17.
The presence of adult barnacles of Fistulobalanus pallidus (Darwin) and Fistulobalanus albicostatus (Pilsbry) attached to field-readable plastic leg rings on the Lesser Black-backed Gull Larus fuscus in Northern Europe is reported. L. fuscus is a long-distance palaearctic migrant, breeding in temperate areas spreading widely over inland and marine habitats outside the breeding season. The species is known to perform long-distance migration to Africa and the Middle East. Combining present knowledge on the birds' migratory pattern and the home range of the barnacle species, it is concluded that the cypris larvae of F. pallidus must have settled in African waters, whereas the area where F. albicostatus settled on the bird leg rings is less certain. The barnacles were of adult size and must thus have been attached for a period of no less than 2 months. More than 30 individual barnacles could occur together on a single field-readable plastic leg ring. The barnacles could therefore, if ported alive to a new area, reproduce successfully and thus either introduce the species or genetically affect other native populations. This may pose a new and wholly unexpected transportation pathway for barnacles as invasive species. 相似文献
18.
ObjectivesThis short commentary examines the factors that led to Food and Drug Administration’s approval of the first plant-derived biologic.ResultsIn 2012, the first plant-derived protein pharmaceutical (biologic) was approved for commercial use in humans. The product, a recombinant form of human β-glucocerebrosidase marketed as ELELYSO, was developed by Protalix Biotherapeutics (Carmiel, Israel). The foresight to select this particular therapeutic product for development, flawless production pipeline, and serendipity seem to provide the key in explaining how ELELYSO became the first plant-derived biologic to achieve approval by Food and Drug Administration.ConclusionsWhile the circumstances that enabled Protalix and its scientists to become the first to arrive at this historic milestone are perhaps unique, it is anticipated that more biologics will follow suit in winning regulatory endorsement. 相似文献
19.
The mevalonate–isoprenoid–cholesterol biosynthesis pathway plays a key role in human health and disease. The importance of this pathway is underscored by the discovery that two major isoprenoids, farnesyl and geranylgeranyl pyrophosphate, are required to modify an array of proteins through a process known as protein prenylation, catalyzed by prenyltransferases. The lipophilic prenyl group facilitates the anchoring of proteins in cell membranes, mediating protein–protein interactions and signal transduction. Numerous essential intracellular proteins undergo prenylation, including most members of the small GTPase superfamily as well as heterotrimeric G proteins and nuclear lamins, and are involved in regulating a plethora of cellular processes and functions. Dysregulation of isoprenoids and protein prenylation is implicated in various disorders, including cardiovascular and cerebrovascular diseases, cancers, bone diseases, infectious diseases, progeria, and neurodegenerative diseases including Alzheimer’s disease (AD). Therefore, isoprenoids and/or prenyltransferases have emerged as attractive targets for developing therapeutic agents. Here, we provide a general overview of isoprenoid synthesis, the process of protein prenylation and the complexity of prenylated proteins, and pharmacological agents that regulate isoprenoids and protein prenylation. Recent findings that connect isoprenoids/protein prenylation with AD are summarized and potential applications of new prenylomic technologies for uncovering the role of prenylated proteins in the pathogenesis of AD are discussed. 相似文献
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